People with chlamydia often do not have symptoms

The Terrence Higgins Trust report says under half of people are seen within two days at clinics in England.

The government has said that by 2008, everyone who needs an appointment should be seen within 48 hours.

But the THT says many areas are a long way from achieving this target.

One of the main aims of our sexual health strategy is to relieve the burden on traditional services by providing screening and testing in a range of different settings such as pharmacies and GP surgeries Department of Health spokeswoman

The government has promised �300m to improve sexual health services in England from next year.

However, THT said there would be no stringent checks in place to ensure this money is put into sexual health services.

Rates of STIs have almost trebled in the last decade and the overall workload for genitourinary-medicine (GUM) clinics has increased by more than 70% since 1997.

In addition, GUM clinics are reporting increases in the number and proportion of complicated STI cases.

The THT said around a third of people with STIs continue to have sex while they wait for a GUM appointment.

Sex infections 'spiralling'

The charity cited data from a Health Protection Agency audit, carried out in May this year, which said only 45% of patients were seen within 48 hours, and 25% of patients had to wait more than two weeks for an appointment.

The audit showed there had been little change over the last year.

Nick Partridge, Chief Executive of Terrence Higgins Trust said "With current waiting times for clinic appointments it's no wonder STI rates are continuing to rise.

"A quarter of people in England have to wait more than two weeks to be seen. It is simply not good enough."

He added: "From 2006 the �300 million allocation will begin to be available to the NHS but it's essential it reaches local frontline sexual health services.

"We now have the worst levels of sexual health since WWII. We must use this opportunity to turn things around.

"Miss it and spiralling sexual health trends will only continue.�

A Department of Health spokeswoman said: "Tackling the rise in sexually transmitted infections is a government priority.

"Sexual health now plays a key role in local delivery plans - in particular, 48 hour access to GUM clinics, reducing gonorrhoea rates and implementing the chlamydia screening programme.

"One of the main aims of our sexual health strategy is to relieve the burden on traditional services by providing screening and testing in a range of different settings such as pharmacies and GP surgeries."